A technician is tasked with clearing all dust covering the fan vents of servers in a small office.Which of the following tools would be the BEST option?（）A、Small vacuumB、Air compressorC、Compressed air canD、Paint brush

A. Small vacuum

B. Air compressor

C. Compressed air can

D. Paint brush

Restrictions occurring in the small orifices(孔) of pneumatic control system components can be caused by ______.

A.moisture in the compressed air supply

B.excessive dryness in the compressed air supply

C.pressure surging in the compressed air receiver

D.insufficient lubrication of the system components

People travel a lot with Heaven Air because they know they will get what they want. They want to go quickly and safely across the land, across the sea or right across the world, and they know Heaven Air will take them where they want to go whenever they want to go. Heaven Air flies all the newest and fastest planes to more towns and cities of the world than any other airlines. Do you want to go to Paris, Washington, Tokyo? Heaven Air will take you there, at all times of the day or night, right through the week. But Heaven Air flies not only to the Biggest cities, we also fly two or three times a week to towns and cities in the very center of Asia, Africa and South America. People fly with Heaven Air because they know they will leave on time and arrive on time. They know that they will receive the best food and watch the best films. Heaven Air is second to none.

1). Heaven Air is the name of ().

2). Travelling with Heaven Air is ().

3). Heaven Air can take you to Paris ().

4). Most flights of Heaven Air go to ().

5). According to the advertisement, Heaven Air believes it is ().

(1).A、a plane

B、an airline

C、a travel service

D、an advertising program

(2).A、comfortable but expensive

B、cheap and pleasant

C、exciting but tiring

D、quick and safe

(3).A、on weekends only

B、just on weekdays

C、any time in a week

D、two or three times a week

(4).A、big cities

B、small towns

C、both big and small cities

D、the very center of Asia

(5).A、the second biggest in the world

B、the second best in the world

C、the biggest in the world

D、the best in the world

A. Air filter

B. Anti-static bags

C. Compressed air

D. Paper bag

Due to the large amount of heat picked up by the air in boiler and engine rooms, it would be impracticable to maintain ambient conditions within the comfort zone by air conditioning or any other means. The normal practice is to provide copious mechanical ventilation; in boiler rooms, the quantity is equated to the combustion requirements, while in a motor ship engine room the supply may be 25-50% in excess of the requirements of the engines.

The axial flow fan is particularly suited to handle these large air volumes at the moderate pressures required, while of course the “straight-through” flow feature places it at an advantage over the centrifugal fan.

The increasing adoption of automation, with the provision of a separate control room makes less significant the fact that comfort conditions cannot be maintained in the engine room all the time. Which of the following devices should be taken to maintain ambient conditions of the boiler and machinery space?

A.air compressor

B.air cooler

C.air-conditioning plant

D.mechanical ventilation plant

In an operating diesel engine, which of the following conditions is an indication of a leaking air starting valve?

A.Noise coming from that air starting valve

B.Continuous operation of the starting air compressor

C.Zero air pressure in the air starting system

D.Overheated starting air pipe to the cylinder head